The present invention relates to certain novel diamine or triamine functional ethylenically unsaturated polymerization compounds. More particularly the present invention relates to such compounds wherein the amine functionally is devoid of active hydrogen groups. Such nonprotic amine compounds may be polymerized by any suitable technique to provide polymers with pendant diamine or triamine functionality.
In U.S. Pat. No. 4,311,799 crosslinked copolymers containing substituted aminoethyl groups are disclosed. The reference discloses that further substituents for the aminoethyl group include aminoalkyls.
In CA 107(8): 59584z and JP 80-11523 polymers of N,N'-diethyl-N-(4-vinylphenethyl)ethylene diamine are disclosed. Because of the existence of an active terminal hydrogen moiety, such monomers are unsuited for use in anionic polymerization processes.
U.S. patent application Ser. No. 352,670, filed May 9, 1989, and assigned to the same assignee as the present application disclosed novel amine containing anionic initiator systems which result in the preparation of block copolymers having narrow molecular weight distribution. The amines employed in such systems were not polymerizable.
Telechelic and block copolymers are well known in the art and are employed for a variety of purposes. Of the block copolymers, those having the configuration AB(BA).sub.n wherein n has a value of from about 1-10, particularly 1, that is block copolymers having a simple ABA, configuration are highly important items of commerce for use in adhesives and as elastomers. The A block is preferably an olefin polymer, especially a styrene homopolymer or copolymer. Usually the B block is an elastomeric polymer, especially a polymer of a diene such as a polymer of butadiene or isoprene. To obtain block copolymers of maximum uniformity, it is usually desirable to initiate polymerization employing a multifunctional lithium compound. In the case of an ABA block copolymer (i.e., a triblock copolymer), a difunctional compound would be employed. In the case of an AB(BA).sub.3 block copolymer, a tetrafunctional initiator would be utilized, etc.
Anionic polymerization is well known in the art, for example U.S. Pat. Nos. 4,431,777 and 4,427,837 disclose suitable anionic polymerization processes. Multifunctional initiators are well known and have been previously used in polymerizations. Such initiators and their use are shown in the following U.S. Pat. Nos.: 4,169,115; 4,172,100; 4,172,190; 4,427,837; 4,196,154; and 4,205,016. The teachings of the preceding patents are incorporated herein by reference thereto.
Particularly desirable multifunctional lithium containing compounds are selected from the group consisting of the formula: ##STR1## wherein R.sub.1 is independently each occurrence hydrogen or an inert radical having from 0 to 16 carbon atoms;
R.sub.2 is a divalent organic radical having at least 6 carbon atoms, R.sub.2 having at least one aromatic ring and the aromatic ring being directly attached to a carbon which is attached to an aromatic ring of the above formula; PA1 R.sub.3 is independently each occurrence selected from the group consisting of alkyl, cycloalkyl, aromatic, mixed alkyl/aromatic, and mixed cycloalkyl/aromatic radicals containing from 1 to 20 carbon atoms. PA1 R is hydrogen or C.sub.1-4 alkyl; PA1 R' independently each occurrence is a C.sub.2-20 difunctional organic group; PA1 R" independently each occurrence is a C.sub.1-20 hydrocarbyl group or an inertly substituted derivative thereof; and PA1 n is one or two.
Especially preferred are initiating compounds of the formula: ##STR2## wherein R.sub.1 and R.sub.3 are as previously defined.
By the term "inert" as used in this context is meant substituents that do not interfere with the desired anionic polymerization. In a most preferred embodiment, R.sub.1 is selected from the group consisting of hydrogen, alkyl, cycloalkyl, alkoxy, aryl and mixtures thereof. Specific examples of difunctional initiators (DFIs) corresponding to the above formula are 1,3-phenylene bis (3-methyl-1-phenylpentylidene)bis(lithium), 1,3-phenylene bis (3-methyl-1-(4-methylphenyl)pentylidene) bis(lithium), 1,3-phenylene bis (3-methyl-1-(4-ethylphenyl)-pentylidene) bis(lithium), 1,3-phenylene bis (3-methyl-1-(4-(1,1-dimethylethyl)phenyl) pentylidene) bis(lithium), and 1,4-phenylene bis(3-methyl-1-(4-dodecylphenyl)-pentylidene) bis(lithium).